What is the national standard for plate thickness?

The thickness deviation of stainless steel plates is allowed to be 0.2 mm.

Normal deviation of stainless steel plate: the general thickness difference of factory standard is ±0.02 mm, and the general thickness difference of national standard is ±0.5 mm. The surface of stainless steel plate is smooth, with high plasticity, toughness and mechanical strength, and is resistant to corrosion by acid, alkaline gas, solution and other media.

The national standard thickness of solid wood flooring is 18 mm. In addition to solid wood flooring, laminate flooring and composite multi-layer solid wood flooring also have standard thickness. The former used to be mainly 8 mm, but now it is mainly 12 mm, and the latter is based on 15 mm!

Solid wood flooring isn't about bigger, but rather the size and specifications that suit your needs. This misconception stems from the fact that larger floors have fewer seams and are more aesthetically pleasing. While larger sizes have their advantages, seams create tension over time, protecting the floor from thermal expansion and contraction, thus ensuring long-term use. The optimal size and specifications for solid wood flooring are under 0.6 meters.

3. National standard for steel plate thickness tolerance

Steel plates are flat, rectangular plates that can be directly rolled or cut from wide steel strips.

Steel plates are classified by thickness: thin steel plates <4 mm (the thinnest is 0.2 mm), thick steel plates 4~60 mm, and extra thick steel plates 60~115 mm.

Steel plates are divided into hot rolled and cold rolled.

Thin plates come in widths of 500-1500 mm, while thick plates range in width from 600-3000 mm. Steel types include ordinary steel, high-quality steel, alloy steel, spring steel, stainless steel, tool steel, heat-resistant steel, bearing steel, silicon steel, and industrial pure iron. Specialized applications include oil drums, enamel, and bulletproof. Surface coatings include galvanized, tinned, leaded, and plastic-clad steel.

Thick steel plates are generally made of the same steel grades as thin plates. In terms of quality, except for bridge plates, boiler plates, automobile plates, pressure vessel plates, and multi-layer high-pressure vessel plates, which are purely thick plates, some types of steel plates, such as automobile beam plates (2.5-10 mm thick), patterned steel plates (2.5-8 mm thick), stainless steel plates, and heat-resistant steel plates, are cross-linked with thin plates.

The thickness of the steel plate is generally allowed to deviate within plus or minus 10%.

General precision requirements: If the steel plate width is less than 1250mm, the tolerance should be within ±0.22mm; if the steel plate width is greater than 1250mm, the tolerance should be within ±0.23mm.

Higher precision requirements: If the steel plate width is between mm, the tolerance should be within ±0.11mm; if the steel plate width is between mm, the tolerance should be within ±0.12mm; if the steel plate width is greater than 1250mm, the tolerance should be within ±0.14mm.

The above two precision requirements are in line with national standards: GB/T stainless steel cold rolled steel plate and steel strip

1. The allowable deviation of angle steel size and shape shall comply with GB/T "Hot-rolled Steel" standard.

2. GB/T "Hot-rolled Steel" standard clearly states:

1) Dimensions, shapes, weights, tolerances, technical requirements, test methods, etc. of hot-rolled equal-leg angle steels, hot-rolled unequal-leg angle steels, hot-rolled L-shaped steels, etc.

2) The mechanical properties, steel grade and chemical composition of the steel section shall comply with the relevant provisions of GB/T700 carbon steel and GB/T1591 low alloy high strength structural steel.

3) Permissible deviation of angle steel size and shape

The national standard steel plate thickness tolerance can be found in the national standard GB "Dimensions, Shape, Weight and Permissible Deviations of Hot-rolled Steel Plates and Steel Strips".

At present, the national standard for aluminum plate thickness is GB/T "Aluminum and aluminum alloy plates and strips". Among them, this standard stipulates the following commonly used aluminum plate thicknesses:

1. Ordinary aluminum plate in hot-rolled state: slow roughing thickness is 4~200mm.

2. Ordinary aluminum sheet in cold-rolled state: thickness is 0.20~6.35mm.

3. Ordinary aluminum plate in casting state: thickness is 6~200mm.

In addition, in actual applications, there are some special requirements and needs that need to be formulated and adjusted according to specific circumstances. Therefore, when selecting and using aluminum plates, it is recommended to refer to relevant industry standards or consult professionals to ensure that the difference meets actual needs.

Thickness of ordinary thin steel plate (mm) 0.20.250.30.350.40.450.50.550.60.70.750.80.91.01.11.21.251.41.51.61.82.02.22.52.83.03.23.53.84.0 Thickness of pickled thin steel plate and galvanized thin steel plate (mm) Nominal size allowable deviation 0......50±0.050.55±0.060.600.65 0.70±0.070.75 0.80±0.080.90 1.00±0.091.10 1.20±0.111.30 1.40±0.121.50 1.60±0.141.80 2.00±0.15 ,Thickness of thick steel plate (mm) 4.555.0

Q235=0.6-0.8, Q345=0.25.

When selecting the negative deviation of steel plate or steel pipe thickness, it should be selected according to the provisions of the corresponding steel standard. When the negative deviation of steel thickness is not greater than 0.25mm and does not exceed 6% of the nominal thickness, the negative deviation of steel thickness can be ignored.

For pressure vessels

Carbon structural steel

The negative thickness deviation of hot-rolled steel plates Q235-B, Q235-C (GB/T912, GB/T3274) and stainless steel hot-rolled steel plates (GB/T4237) shall comply with the provisions of GB/T on the size, shape, weight and allowable deviation of hot-rolled steel plates and steel strips.

When stainless steel cold-rolled steel plates (GB/T3280, thickness not exceeding 4mm) are selected, the negative thickness deviation shall comply with the size, shape, weight and allowable deviation provisions of GB/T cold-rolled steel plates and steel strips; the negative thickness deviation of composite steel plates and seamless steel pipes shall comply with the corresponding steel material standards.

Additional information:

Steel precautions:

1. The principle requirement of stacking is to stack materials by type and specification under the condition of stable and safe stacking. Different types of materials should be stacked separately to prevent confusion and mutual corrosion.

2. Steel sections stacked in the open air must have wooden pads or stone slabs underneath, and the stack surface must be slightly tilted to facilitate drainage. Pay attention to placing the materials straight to prevent bending and deformation.

3. The stacking height shall not exceed 1.2m for manual operation and 1.5m for mechanical operation, and the stacking width shall not exceed 2.5m.

4. Raise the bottom of the stack. If the warehouse has a cement floor facing the sun, it only needs to be raised by 0.1m. If it is a mud floor, it needs to be raised by 0.2-0.5m. If it is an open-air site, the cement floor should be raised by 0.3-0.5m, and the sand and mud surface should be raised by 0.5-0.7m.

5. Angle steel and channel steel should be stacked face down when in the open air, that is, the mouth should face down, I-beams should be placed upright, and the I-groove surface of the steel should not face upward to avoid water accumulation and rust.

Reference sources:

Baidu Encyclopedia - Board

Reference sources:

Baidu Encyclopedia - Steel

Reference sources:

Baidu Baiban Car Technology-Q235

Reference sources:

Baidu Encyclopedia - Q345

Reference sources:

Baidu Encyclopedia - Thickness Permissible Deviation

Reference sources:

Baidu Encyclopedia - Stainless Steel Cold-Rolled Steel Plate

Q235=0.6~0.8

Q345=0.25

The "Pressure Vessel Design Engineer Training Course 2005" explains the negative thickness deviation as follows:

1. When selecting the negative deviation of steel plate or steel pipe thickness, it should be selected according to the provisions of the corresponding steel standard.

2. When the negative deviation of the steel thickness is no more than 0.25mm and does not exceed 6% of the nominal thickness, the negative deviation of the steel thickness can be ignored.

3. The negative deviation of the thickness of steel plates used for pressure vessels in my country is 0.25.

4. For carbon structural steel hot-rolled steel plates Q235-B, Q235-C (GB/T912, GB/T3274) and stainless steel hot-rolled steel plates (GB/T4237) for pressure vessels, the negative thickness deviation shall be determined in accordance with the provisions of GB/T "Dimensions, Shapes, Weights and Permissible Deviations of Hot-rolled Steel Plates and Steel Strips".

When stainless steel cold-rolled steel plates (GB/T3280, thickness not exceeding 4mm) are selected, the thickness tolerance shall comply with the provisions of GB/T "Dimensions, Shape, Weight and Permissible Deviations of Cold-Rolled Steel Plates and Strips".

The negative thickness deviation of composite steel plates and seamless steel pipes shall be in accordance with the corresponding steel standards.